1. Field of the Invention
This invention relates to motion image recording apparatuses and, more particularly, to a motion image reproducing apparatus which is applicable to a digital camera for reproducing motion image data recorded on a recording medium.
2. Description of the Prior Art
In the conventional motion image reproducing apparatus of this kind, the reproduced motion image data from the recording medium must be once stored in an internal memory. The data is thereafter outputted to a monitor through processing by a JPEG CODEC. For example, where reproducing 30 seconds of motion image data recorded on a recording medium, this 30-seconds motion image data in its entirety is first stored in the internal memory. Thereafter, the data is subjected to decompression on 1-frame basis, being outputted onto the monitor.
In the prior art, however, there is a necessity to store all the reproducing motion image data to the internal memory. This results in a problem that the amount of data reproducible is relied upon a memory capacity.
It is therefore a primary object of the present invention to provide a motion image reproducing apparatus which is capable of reproducing motion images for a long time period regardless of a memory capacity.
In accordance with the present invention, a motion image reproducing apparatus for reproducing a data file containing a plurality of frames of image data and image administrating information to administrate the plurality of frames of image data, thereby displaying motion images on a monitor, comprising: a selector for selecting each of a plurality of frame numbers at a predetermined time interval; an image data reader for reading 1 frame of image data out of the data file based on a frame number selected by the selector and the image administrating information; an image data writer for writing the 1frame of image data read out by the image data reader to an internal memory; and a display circuit for displaying a still image on the monitor based on the 1 frame of image data written in the internal memory.
When reproducing is made on a data file to display motion images on the monitor, selector selects each of a plurality of frame numbers at a predetermined time interval. The image data reader reads out 1 frame of image data out of the data file based on a frame number selected by the selector and image administrating information. The read-out 1-frame image data is written to the internal memory by the image data reader. The display circuit causes a still image to be displayed on the monitor based on the written 1-frame image data in the internal memory. Because the frame numbers are selected at the predetermined time interval, the corresponding one of image data to the frame numbers are read from the data file at the predetermined time interval and written to the internal memory at the predetermined time interval. Due to this, on the monitor is displayed a motion image constituted by a plurality of still images.
In accordance with the invention, the image data is written frame by frame to the internal memory in an intermittent fashion so that still images can be displayed on the monitor based on the each-framed image data written in the internal memory. It is therefore possible to reproduce a long-time motion image even if the internal memory is small in capacity.
In one embodiment of the invention, the image administrating information includes a beginning address of each frame of image data.
In another embodiment of the invention, the 1 frame of image data written in the internal memory is renewed by image data read out with delay by the image data reader.
In still another embodiment of the invention, the internal memory has at least two storage areas to store the 1 frame of image data. The display circuit displays the still image on the monitor based on the 1 frame of image data written in one of the storage areas. On the other hand, the image data writer writing the 1 frame of image data to a storage area not under a display process.
In yet another embodiment of the invention, the image data is compressed data having been compressed according to a predetermined scheme, and the display circuit including a decompression circuit and an output circuit. The decompression circuit decompresses the 1 frame of image data written in the internal memory, and the output circuit outputs to the monitor image data having been decompressed by the decompression circuit. Here, the predetermined scheme is preferably JPEG.
In another embodiment of the invention, the data file further includes sound data related to the plurality of frames of image data and sound administrating information to administrate the sound data. A sound data reader reads sound data related to 1 frame out of the data file based on a frame number selected by the selector and the sound administrating information. A sound output circuit outputs at a predetermined timing the sound data read out by the sound data reader. Here, the data file preferably accommodates alternately a predetermined time period of sound data and image data in a corresponding number of frames to the predetermined time period.
In accordance with the present invention, a motion image reproducing apparatus for reproducing a first number of frames of image data and a data file containing image administrating information to administrate the first number of frames of image data, thereby displaying motion images on a monitor, comprising: a selector for selecting each of a plurality of frame numbers at a predetermined time interval; an image data reader for reading a second number of frames of image data less than the first number of frames out of the data file based on a frame number selected by the selector and the image administrating information; an image data writer for writing the second number of frames of image data read by the image data reader to an internal memory; and a display circuit for displaying corresponding motion images to the second number of frames on the monitor based on the second number of frames of image data written in the internal memory.
When reproducing is made on a data file to display motion images on the monitor, selector selects each of a plurality of frame numbers at a predetermined time interval. The image data reader reads, out of the data file, image data in a second number of frames less than a first number of frames based on a frame number selected by the selector and image administrating information. The read-out image data in the second number of frames is written to the internal memory by the image data reader. The display circuit causes motion images in the second number of frames to be displayed on the monitor based on the written image data in the second number of frames in the internal memory. Because the frame numbers are selected at the predetermined time interval, the related second number of frames of image data to each of the frame numbers are read from the data file at the predetermined time interval and written to the internal memory at the predetermined time interval. Due to this, on the monitor is displayed a motion image constituted by the greater number of frames than the second number of frames.
In accordance with the invention, the image data is written in an amount of the second number of frames a time to the internal memory in an intermittent fashion so that a motion image can be displayed on the monitor based on the image data written in the internal memory. It is therefore possible to reproduce a long-time motion image even if the internal memory is small in capacity.
In one embodiment of the invention, the image data is compressed data having been compressed according to a predetermined scheme, and the display circuit including a decompression circuit and an output circuit. The decompression circuit decompresses the second number of frames of image data written in the internal memory, while the output circuit outputs the second number of frames of image data decompressed by the decompression circuit to the monitor.
In another embodiment of the invention, the data file further includes sound data related to the first number of frames of image data and sound administrating information to administrate the sound data. A sound data reader reads sound data related in time period to the second number of frames out of the data file based on a frame number selected by the selector and the sound administrating information. A sound output circuit outputs at a predetermined timing the sound data read out by the sound data reader.